Furnace.



PATENTED MAR. 17', 1903.

J. ARMSTRONG.

FURNAGE. APPLIUATION FILED OUT. 6, 1902.

so MODEL.

FIGJ.

wi asses NITED STATES I FFICE.

ATENT FURNACE.

SPECIFICATION forming part of Letters PatentNo. 722,932, dated March 17, 1903.

Application filed October 6,1902. serialNe.-126,Z2 8. (No model.)

To all whom it may concern:

Beit known that 1, JOHN ARMSTRONG, civil engineer, a subject of the King of Great Britain, residing in the city of London, England,

(whose full postal address is 46 Lombard street, London, aforesaid,) have invented cer-' poses where complete combustion is required and very high temperatures can be obtained.

In my former patent, No. 705,312, it will-be observed that the design of that invention was not for the purpose of complete combustion of the fuel to carbonic acid, but, on the contrary, the formation of carbon mono'xida reducing-gasfor the purposes mentioned in that patent. ever, I have modified the apparatus and made arrangements for the purpose of the complete combustion of the fuel. It will also-be shown, together with the last-named object, that the operator can with the present invention havecomplete control of the heat developed by means of primary and secondary air-blastinlets, steam-jets, &c. Provision is made for the reservation of all the unaltered fuel at'the rear of the consumption or oxidizing hearth, thus preventing the raw fuel attaining the surface of that part ofv the fire wherethefuel is properly consumed, whereby smoke is prevented, the object being to have a constantly clear fire always exposed to the furnacehearth to be heated.

Figures 1 and 2 show longitudinal sections of two slightly-different forms of my apparatus asapplied to a reverberatory furnace for puddling iron, melting steel, smelting or refining copper, or for other like purpose.

It will be seen that :1: w represent the hearth of an ordinary puddling-furnace.

y is the lower bridge.

(0 a represent the grate, which can be of any In the present invention, how

ordinary type, but is here shown constructed of a plate perforated with numerous conical holes allover its surface.

1) is a frame set into the brickwork for holding the above grate, and 0 represents plates connected with the frame I) and dipping down beneath the surface of the water w w in Fig. 2, thereby forming an air-chamber d d.

A door is provided at n, which can be moved on-hinges against the dead-plate o. This door isusedfor the purpose of pushing forward thefire and removing clinkers. The space 19 p is the reservoir containing the fuel. This may be surmounted by a cup-andcone apparatus or a shot-flask apparatus (not shown) for the purpose of letting down the fuel without allowing the smoke or gas to escape. This chamber is shown of solid brickwork. There is a front upper pendent bridge provided at s, which keeps the fuel back until that which is on the grate is consumed.

There are doorsm; provided, preferably at both sides-of the furnace, although one may be used for the purpose of spreading the fuel or removing clinkers. The line of the fuel is shown at g g, which descends upon the grate at an angle. 'A primary blast of air is supplied from a blower .by the pipe 6, which air passing into the fire from the air-chamber d d consumes the fuelimmediately upon the grate to carbonic acid. The smoke and gas produced by the heat radiating into the chamber 10 p and finding no outlet at the top are made to traverse the incandescent coke at furnace unconsumed,because the atmospheric air blown in through the'grate having to traverse so much incandescent coke becomes deoxidized, and thereby incapable of consuming these gases. To prevent this, a heatingchamber is constructed, filled loosely with bricks, over the furnace-roof at Z. A secondary air-blast is made to traverse this chamber Z, whereby the air is heated and descends through the apertures t, whereby all these gases are completely consumed and the action of the heated air, together with the rear upper pendent bridge '1", Fig. 1, directs the flame down upon the hearth.

2 is an air-blast pipe connecting the primary air-blast with the heating-chamber. In

Fig. 1 this air-blast pipe z isshown connected directly with the primaryair-lolast pipe';butin Fig. 2 it is shown con'nectedwith the primary air-blast chamber.

Where there is no convenient source of power for blowing purposes, a steam-jet may be used, as at ff, and such steam may be beneficial, especially when working with fuel of a very inferior nature. The action of the steam in such case is twofold. In the first place, it is used to soften and break up the clinker, and, in the second place, passing in with the air through the incandescent fuel, it is decomposed and split up into carbon monoxid and hydrogen gases. These are consumed, as has been already stated, by means of the secondary air-inlets at t. The steam, however, supplies no additional heat and is often deleterious. When, therefore, the blast is eifected by steamjets, I may bring the entire blast down through or in close contact with water by means of a downwardlyinclined blast-pipe e, as shown in Fig. 2, whereby most of the steam is condensed, and so does not enter the furnace with the air.

Fig. 1 shows the air-chamber constructed as a box for collectingany dust that may fall through the apertures in the grate CL. Means are provided for removing this dust by the valve S. In Fig. 2 the dust falls into the water and can from time to time be raked out through any side aperture. (Not shown.)

Apertures h are provided above the door n for the purpose of inserting spears for holding up the fuel while the grated ctis dropped. A valve is provided in Fig. 1 at S for the purpose of clearing away any dust. I

The air-blast, whether by means of an airblower or by means of a steam-jet or compressed-air jet, whether as primary or secondary, is provided with the usual cocks and valves (not shown) for regulation.

For reverberatory-furnace purposes it will -be evident that the forcing in of the air or air and steam is for the purpose of completely consuming the fuel without the aid of a draft by means of a chimney-stack. By this means the furnace can be easily made to have a plus-pressure atmosphere in its interior, whereby the entrance of the cold atmosphere or oxidizing drafts so destructive in metallurgical and other operations is entirely avoided. Although these applications have been shown for reverberatory and other fornace Work, they can be made applicable to ovens for baking bread or biscuits, for baking or firing pottery or bricks in kilns, where they are made to take the place of the ordinary fire-grate. Any number of these grates can be placed around a furnace or kiln.

This furnace may be used as a destructor by supplying the refuse to be destroyed,either with orwithout fuel,into the compartmentpp.

As this furnace burns the fuel as well as all the gas and smoke produced to carbonic acid, the full theoretical amount of calories may be obtained by it. It will therefore be more economical in use practically than gas furnaces generally or ordinarily -.fired furnaces, because all the initial heat of the complete oxidation of the fuel to CO is thrown direct and immediately into the furnacehearth a: a: without loss and the highest temperature obtained. The grate a a being solid, only being perforated with small holes, no unconsumed fuel is allowed to drop through, and this grate at a being placed in immediate contiguity to the furnace-hearth {.1}, while the raw fuel is kept behind the bridge .9 over the dead-plate o, the surface of the incandescent fuel over the grate a a is always bright and no cold fuel comes upon its surface. Consequently the full heat is unrestricted. This is veryimportant in certain metallurgical operations and in the heating or firing of retorts where it is used. By the regulation of the valves of the primary and secondary air a neutral reducing or oxidizing atmosphere can be maintained at will.

This invention differs from all that has gone before in these respects: that the supply of oxygen can be exactly regulated, the whole of the oxygen of the air passing through the grate being under pressure passed in in regulated quantities and largely converted into carbonic oxid, and as the amount of air passing through the air-inlets t can be regulated exactly all the carbonic oxid can be converted without waste intocarbonic acid, while at the same time as the coal is delivered at the front of the grate and by gravity settles to the back of the grate after it has been to a considerable extent coked there is always a brilliant-red surface exposed to the furnace-hearth, while by using the device set forth in Fig. 2 the entire blast can be effected by steam -jet without any sensible amount of steam escaping into the furnace, and there being always a plus pressure in the furnace leakage inward is impossible, and thus even when working doors are opened the action of the furnace remains constant.

I declare that what I claim is l. A furnace comprisinga grate-frame having a grate, a bridge, a dead-plate located in front of the grate-frame, a reservoir through which the fuel extends over the dead-plate and the grate to the bridge, an air-chamber located beneath the grate, a primary air-blast pipe extending into the air-chamber, an upper heating-chamberhaving secondary airblast inlets located in rear of the fuel, and

an air-blast pipe connecting the primary air- In witness whereof I have hereunto signed my name, this 24thday of September, 1902, in the presence of two subscribing witnesses.

JOHN ARMSTRONG.

chamber 01, beneath the grate; water-chamber 20; steam-pipe f, having a jet-pipe f; and downwardly-inclined blast-pipe e adapted to deliver the blast below the surface of water in chamber w; whereby steam is condensed and air delivered under pressure to the furnace, substantially as described.

Witnesses:

W. P. THOMPSON, H. P. SHOOBRIDGE. 

